<aside class="sidebar">
    <div *ngFor="let i of data; let idx = index" (mouseover)="onMouseOver(idx)" class="group">
        <div class="title" [routerLink]="['/item-group',i.id]">{{i.id}}F&nbsp;{{i.title}}</div>
        <div class="content" [class.show]="curIdx === idx">
            <a [routerLink]="['/item-group',i.id]">{{i.desc}}</a>
        </div>
    </div>
</aside>
